This research aims to analyze the factors that affect communication breakdown in students speaking performance, especially in terms of oral fluency. It focuses on interpersonal skills such as confidence, anxiety, and listening ability to the instruction, as well as the language learning aspects such as classroom environment and learning styles. This research was conducted due to students struggles with speaking English fluency during classroom activities. The study used a qualitative research design. Data were collected through classroom observations and interview with 35 students at SMAN 1 Kalisat. The observation focused on students’ behaviors during speaking activities, while the interviews explored their personal experiences with communication difficulties. The findings revealed that communication breakdowns were influenced by two main factors: interpersonal skills and language learning factors. Interpersonal skills factors included low confidence, anxiety, lack of motivation, and poor listening ability to the teacher’s instructions. Then language learning factor involved limited vocabulary, grammar difficulties, and unsupportive classroom environment. These factors led to common causes of communication breakdown, such as hesitation, fear of making mistakes, silence during speaking activities and difficulty in expressing ideas clearly. In conclusion, this research found that both interpersonal skill and language learning factors contribute significantly to communication breakdown in speaking. To overcome these issues, teachers are encouraging to create a more supportive learning environment and provide more interactive and confidence building speaking opportunities.